New record of Hypselodoris infucata (Rüppell & Leuckart, 1830) (Mollusca, Gastropoda, Chromodorididae) in the Republic of Mauritius

To date, 179 species belonging to the gastropod infraclass Euthyneura are known from Mauritius. We report for the first time from Mauritius the chromodorid nudibranch, Hypselodoris infucata (Rüppell & Leuckart, 1830), based on 47 sites surveyed over 17 months. This species was previously known from the eastern Mediterranean Sea, Indo-Pacific Ocean, and Western Indian Ocean. We observed it in Mauritius at Bain des Dames near a shipwreck under coral rubble. Considering the small size and camouflage behavior of some nudibranch species, additional fieldwork will likely add others species unknown from the islands.

A Comparison of Size, Shape, and Fractal Diversity Between Coral Rubble Sampled From Natural and Artificial Coastlines Around Okinawa Island, Japan

Substrate surface area and fractal complexity have been reported to influence the abundance and diversity of mobile cryptic animal communities. Surfaces with higher fractal dimensions not only offer additional space for colonization, but bias space availability toward smaller size ranges, increasing the number of available niches. Conversely, smaller surface areas tend to be associated with a decrease in abundances while reduced fractal complexities may support less diversity in the benthic community. In this study, we compared morphological parameters between rubble sampled from rubble mounds accumulated at the seaward side of artificial breakwaters and rubble sampled from a nearby location with no breakwaters (=control site). The purpose of this work was to establish a methodology for comparing the surface area and fractal complexity of coral rubble fragments using easily available equipment that could be efficiently utilized during field work. Rubble fragments were individually weighed and photographed in controlled light conditions. Each photograph was then analyzed using ImageJ software. Rubble pieces from each photograph went through segmentation, the separation of sample outlines from the picture background, before being measured and analyzed for surface area, width, and length (size estimators), and circularity, aspect ratio, roundness, solidity, and Feret properties (shape estimators). Surface fractal complexity was also measured, using the box counting method on segmented rubble surfaces. We observed lowered surface areas, weight, and fractal complexity for rubble fragments sampled at the breakwater. We demonstrate how this method could be used to compare coral rubble from a variety of environmental conditions, thus becoming a useful aid in environmental monitoring, in addition to adding important information to the collection and analyses of biological data.

Representative benthic habitat mapping on Lovina coral reefs in Northern Bali, Indonesia

Kartikasari A, Pristianto T, Hanintyo R, Ampou EE, Wibawa TA, Borneo BB. 2021. Representative benthic habitat mapping on Lovina coral reefs in Northern Bali, Indonesia. Biodiversitas 22: 4766-4774. Satellite optical imagery datasets integrated with in situ measurements are widely used to derive the spatial distribution of various benthic habitats in coral reef ecosystems. In this study, an approach to estimate spatial coverage of those habitats based on observation derived from Sentinel-2 optical imagery and a field survey, is presented. This study focused on the Lovina coral reef ecosystem of Northern Bali, Indonesia to support deployment of artificial reefs within the Indonesian Coral Reef Garden (ICRG) programme. Three specific locations were explored: Temukus, Tukad Mungga, and Baktiseraga waters. Spatial benthic habitat coverages of these three waters was estimated based on supervised classification techniques using 10m bands of Sentinel-2 imagery and the medium scale approach (MSA) transect method of in situ measurement.The study indicates that total coverage of benthic habitat is 61.34 ha, 25.17 ha, and 27.88 ha for Temukus, Tukad Mungga, and Baktiseraga waters, respectively. The dominant benthic habitat of those three waters consists of sand, seagrass, coral, rubble, reef slope and intertidal zone. The coral reef coverage is 29.48 ha (48%) for Temukus covered by genus Acropora, Isopora, Porites, Montipora, Pocillopora. The coverage for Tukad Mungga is 8.69 ha (35%) covered by genus Acropora, Montipora, Favia, Psammocora, Porites, and the coverage for Baktiseraga is 11.37 ha (41%) covered by genus Montipora sp, Goniastrea, Pavona, Platygyra, Pocillopora, Porites, Acropora, Leptoseris, Acropora, Pocillopora, Fungia. The results are expected to be suitable as supporting data in restoring coral reef ecosystems in the northern part of Bali, especially in Buleleng District.

An annotated and illustrated checklist of the porcelain crabs of Panama (Decapoda: Anomura)

The present study is the first exhaustive checklist of porcelain crabs (Porcellanidae) distributed on the Pacific and Atlantic (Caribbean) coasts of Panama, based on literature records and material collected between 2006 and 2019. The Panamanian porcellanid fauna is currently composed of a total of 76 species, with 26 species reported from the Caribbean coast, 45 species reported from the Pacific coast, and five species reported from both sides of the Central American Isthmus (Isthmus of Panama). In other words, the Caribbean and Pacific coasts of Panama each harbour, respectively, 31 and 50 species of porcellanid crabs. However, this total includes two problematic porcellanid records from Panama, viz. Clastotoechus nodosus (Streets, 1872) and Petrolisthes brachycarpus Sivertsen, 1933, as well as a putatively undecribed taxon reported as Pachycheles sp. The following four species are recorded for the first time from Panama, viz. Euceramus panatelus Glassell, 1938, Pachycheles riisei (Stimpson, 1859) [also being new for Mexico], Petrolisthes dissimulatus Gore, 1983 and P. tonsorius Haig, 1960. In addition, Minyocerus kirki Glassell, 1938 is newly recorded from Colombia, extending its previously known distributional range significantly southwards. Most species are illustrated in colour, several for the first time, based on material from Panama or other localities. At least 20 further species (16 in the Atlantic, 5 in the Pacific, and 1 in both oceans) are suspected to occur in Panamanian waters, based on their records from the neighbouring Costa Rica and/or Colombia, or their wide distribution in the Caribbean Sea or the tropical eastern Pacific. The presence of several cryptic or pseudocryptic species (at least some of them presumably undescribed), especially in the taxonomically challenging Petrolisthes galathinus (Bosc, 1802) species complex, or the eventual species splitting within some taxa currently seen as transisthmian, will likely further increase the total number of species present in Panama. The porcellanid fauna of Panama is also ecologically remarkably diversified. Most Panamanian porcelain crabs are free-living under rocks, in crevices of rocks, dead coral heads, coralline algae, coral rubble etc., or on mud, among mangrove roots. Euceramus panatelus lives in possibly self-dug burrows in soft mud or muddy sand, whereas its congener E. transversilineatus (Lockington, 1878) may occasionally be found in association with holothuroids. At least 15 further porcellanid species occurring in Panama live in permanent or facultative associations with a variety of other marine organisms, including sponges, cnidarians (octocorals), echinoderms (sea urchins, sea stars, sea cucumbers), polychaetes (parchment worms) and other decapod crustaceans (hermit crabs), making them one of the most attractive groups for studies of symbiosis-related behaviour and evolution.

On the occurrence of Antillesoma antillarum (Grube, 1858) (Sipuncula, Antillesomatidae) on the south-central part of the Colombian Caribbean coast

We document here the first confirmed report of the sipunculan worm Antillesoma antillarum (Grube, 1858) based on freshly collected, taxonomically verified specimens from the south-central Colombian Caribbean coast. This species was encountered on massive coralline rocks, coral rubble, and coral boulder at San Antero. We briefly describe and illustrate this species and provide notes on its distribution, ecology, and habitat.

KOMPARASI POLA SPASIAL KONDISI TERUMBU KARANG TAMAN NASIONAL KARIMUNJAWA

ABSTRACTComparative studies on the percentage of coral reef substrate cover have been carried out in 3 (three) management zones (protection zone, utilization and Non-MPA) Karimunjawa National Park (KNP). The Manta Tow broadscale coral reef assessment method was applied to the north side of Bengkoang Island and the south side of Cemara Besar Island (protection zone), southern side of Bengkoang Island and northern side of Cemara Besar Island (utilization zone) and Non-MPA (Seruni Island) to observe live coral cover, dead coral, coral rubble and soft coral. Substrate cover variations from 10-12 towing (track length 200m) from each side of the island have formed a spatial pattern of coral reef conditions. Furthermore, the condition of the coral reefs was confirmed using the UPT (Underwater Photo Transect) detailed assessment method with one station on each side of the island. The results showed that there were differences in the spatial pattern of coral reef conditions as indicated by significant differences in the percentage of live coral cover, dead coral, rubble and coral lifeform among management zones of the KNP. The condition of coral reefs of the MPA is better and has a higher diversity of coral species than Non-MPA of the Karimunjawa National Park. The spatial pattern of coral reef conditions can be used as an indicator of disturbances in the coral reef ecosystem and can be used for periodic analysis of coral reef monitoring data in conservation areas.Keywords: spatial pattern, coral reef condition, manta tow, underwater photo transect, Karimunjawa National Park.ABSTRAKStudi perbandingan persentase tutupan substrat terumbu karang telah di lakukan pada 3 (tiga) zona pengelolaan (zona perlindungan, pemanfaatan dan luar kawasan) Taman Nasional Karimunjawa. Metode penilaian terumbu karang skala luas Manta Tow diaplikasikan di sisi utara P. Bengkoang dan sisi selatan P. Cemara Besar (zona perlindungan), sisi selatan P. Bengkoang dan sisi utara P. Cemara Besar (zona pemanfaatan) dan luar kawasan (P. Seruni) untuk mengamati tutupan karang hidup, karang mati, pecahan karang dan karang lunak. Variasi persentase tutupan substrat dari 10-12 tarikan Manta Tow (panjang lintasan 200m) dari masing-masing sisi pulau telah membentuk pola spasial kondisi terumbu karang. Selanjutnya penilaian kondisi terumbu karang dikonfirmasi dengan menggunakan metode penilaian rinci UPT (Underwater Photo Transect) dengan satu stasiun setiap sisi pulau. Hasil menunjukkan terdapat perbedaan pola spasial kondisi terumbu karang yang ditunjukkan oleh perbedaan yang signifikan persentase tutupan karang hidup, karang mati, pecahan karang dan lifeform karang antar zona pengelolaan. Kondisi terumbu karang di dalam kawasan lebih baik dan memiliki keragaman jenis karang lebih tinggi daripada di luar kawasan Taman Nasional Karimunjawa. Pola spasial kondisi terumbu karang dapat dijadikan indikator terjadinya gangguan pada ekosistem terumbu karang di suatu kawasan dan dapat digunakan untuk analisis data pemantauan terumbu karang secara berkala di kawasan konservasi.Kata Kunci: pola pasial, kondisi terumbu karang, manta tow, underwater photo transect, Taman Nasional Karimunjawa,

Gastropods in the Intertidal Shore of Kota Kinabalu, Sabah (Malaysian Borneo)

Intertidal gastropods provide numerous ecological benefits and are responsible for the dynamics of the intertidal shores habitat and its community assemblages. This study examined the community structure of gastropods in the intertidal shore located near the city of Kota Kinabalu, the capital of Sabah where coastal areas are rapidly developed for various purposes and consequently destroying natural habitats. A total of 36 gastropods species from 15 families were recorded. The Planaxis sulcatus was the most abundant species with a density of 480 ind. m-2 followed by Nodilittorina pyramidalis (182 ind. m-2) and Cellana radiata (97 ind. m-2) respectively. The number of species and their abundance, respectively, are almost three times lower than the number ever recorded for intertidal shores located in non-urban areas or remote locations. This suggests that the rapidly growing coastal urban areas threatening the diversity and abundance of intertidal gastropods. The density of gastropod (i.e. P. sulcatus & N. pyramidalis) was significantly (p<0.05) high at the lower intertidal shore where slope gradient is steeper with rocks and crevices are the major component of substrates compared to the upper or middle zone which is flatter and composed mainly of coral rubble and sand. Our study suggests that gastropod communities in intertidal shores located adjacent to the urban areas are threatened especially by anthropogenic factors such as frequent human visitations and modification of natural habitat. Future development in the intertidal shore should minimise habitat destruction and should consider infrastructures that encourage gastropod populations to grow and highlighting their ecological role for conservation reasons.

Nitrogen fixation and denitrification activity differ between coral- and algae-dominated Red Sea reefs

Coral reefs experience phase shifts from coral- to algae-dominated benthic communities, which could affect the interplay between processes introducing and removing bioavailable nitrogen. However, the magnitude of such processes, i.e., dinitrogen (N2) fixation and denitrification levels, and their responses to phase shifts remain unknown in coral reefs. We assessed both processes for the dominant species of six benthic categories (hard corals, soft corals, turf algae, coral rubble, biogenic rock, and reef sands) accounting for > 98% of the benthic cover of a central Red Sea coral reef. Rates were extrapolated to the relative benthic cover of the studied organisms in co-occurring coral- and algae-dominated areas of the same reef. In general, benthic categories with high N2 fixation exhibited low denitrification activity. Extrapolated to the respective reef area, turf algae and coral rubble accounted for > 90% of overall N2 fixation, whereas corals contributed to more than half of reef denitrification. Total N2 fixation was twice as high in algae- compared to coral-dominated areas, whereas denitrification levels were similar. We conclude that algae-dominated reefs promote new nitrogen input through enhanced N2 fixation and comparatively low denitrification. The subsequent increased nitrogen availability could support net productivity, resulting in a positive feedback loop that increases the competitive advantage of algae over corals in reefs that experienced a phase shift.

Second finding, first complete specimen and range extension of the rare alpheid shrimp Bermudacaris britayevi Anker, Poddoubtchenko & Marin, 2006 (Caridea: Alpheidae)

The very uncommon alpheid shrimp Bermudacaris britayevi Anker, Poddoubtchenko & Marin, 2006, previously known only from the incomplete holotype from Nha Trang Bay, Vietnam, is recorded from Guam, Mariana Islands, extending its previously known distribution range into the oceanic islands of the western Pacific. The single specimen from Guam, an ovigerous female, was collected adjacent to a near-shore coral reef, on fine sand under a large piece of coral rubble, at a depth of about 10 m. This habitat is different from the collection data of the holotype, which was extracted from a burrow of unknown host on an intertidal sand-mud flat close to mangroves. Despite these ecological differences, the specimen from Guam corresponds to the holotype of B. britayevi in all diagnostic morphological characters and can be distinguished from the closely related B. australiensis Anker & Komai, 2004 and B. harti Anker & Iliffe, 2000. Since the holotype of B. britayevi was lacking one of the chelipeds, the complete specimen from Guam enables to complement the original description of the species. The stouter (= major) cheliped of the Guam specimen is illustrated to show a marked difference in the armature of the cheliped fingers, between the left and right cheliped. The colour pattern of B. britayevi, which was superficially described in the original description, is herein illustrated by photographs of the living individual. The relatively low number and large size of eggs in the Guam specimen of B. britayevi suggests an abbreviated larval development in this species.